With the aim(lens) to evaluate different doses of the lnoculante Rhizocaj with Vine-stock You Knock down "61" of the bacterium (Rhizobium japonicum) to determine the effects on the yield of grain of Soy bean and to determine the relation benefit - cost of the best treatment There was realized a comparative test(essay) of 6 treatrnents. where a maximurn yield of grain was reached with T4 (3757 53 Kg/ha) followed(continued) of T3 (3678.12 Kg/ha). The experiment 1 carry out in the Sector Oasis, district of Mulberry trees(moralities), province of St Martin, Region St Martin, in a soil that has the following characteristics: texture sandy Franc, pH = 6 98, rich in potassium (0 .5 meq/100 gr.), High phosphorus (27 O ppm) and average nitrogen. The experimental disposition(regulation) employee was of block Completely Randomizado with six treatments and four repetitions, four ruts for every unit,...